cubicweb-tag #2493898 upgrade to cw 3.15 [done]

prioritynormal
typeenhancement
done in1.8.0
load left0.000
closed by#c6f15fbe900f [entities,views] finish cw 3.15 compat (closes #2493898), #f55e4740ed90 [cw] upgrade to cubicweb 3.15 (closes #2493898)